Panonychus ulmi is an economically important, plant-feeding mite found on apple and other related deciduous trees throughout the apple-growing regions of the world. (Sandra J. Walde, Chapter 9 - Internal Dynamics and Metapopulations: Experimental Tests with Predator—Prey Systems, Editor(s): Naomi Cappuccino, Peter W. Price,
Population Dynamics, Academic Press, 1995, ISBN 9780121592707,
https://doi.org/10.1016/B978-012159270-7/50010-5.)
Econometrics uses economic theory, mathematics, and statistical inference to quantify economic phenomena. In other words, it turns theoretical economic models into useful tools for economic policymaking. (IMF. 2011. What Is Econometrics? https://www.imf.org/external/pubs/ft/fandd/2011/12/basics.htm)
It primarily uses monetary values as a measure to allow policy makers to compare costs and benefits from different types of goods and services. It encompasses more than the study of market goods and services. Economic analysis does not prevent the use of other measures that do not use a monetary value; for example, qualitative or environmental analysis. (IPPC Secretariat. 2021. Glossary of phytosanitary terms. International Standard for Phytosanitary Measures No. 5. Rome. FAO on behalf of the Secretariat of the International Plant Protection Convention.)
